Spinning nozzles



United States Patent SPINNING NOZZLES Konrad Ruthardt, Goethestrasse 19 Hanan (Main),

Germany N0 Drawing. Filed Feb. 20, 1958, Ser. No. 716,517

5 Claims. (Cl. 75-172) The invention concerns spinning nozzles for the production of synthetic filaments, especially artificial silk and rayon, which mostly consist of precious metals and alloys thereof, for example, of platinum-gold alloys.

This application is a continuation-in-part of my copending application Serial No. 597,532, filed July 12, 1956, now abandoned.

Spinning nozzles have to answer various demands. The material of which they consist must be capable of being easily machined and to render high polished surfaces in order that orifices of highest hardness and polish may be produced. Alloys hardened by heat treatment have the advantage that they can be machined when soft, and then brought to a high degree of hardness, which is of great value because of the great stress exerted thereon in operation.

Valuable alloys for spinning nozzles have already been developed. Yet there exists in the spinning industry the demand for materials which warrant uniform spinning results even after a long use of the spinning nozzle. The present invention fulfills the demand for a spinning nozzle of outstanding durability.

It has been discovered that palladium-iridium alloys of a specific composition fulfill the requisites of a material for spinning nozzles in chemical as well as in mechanical respect. An addition of to 30% iridium, most preferably of to of iridium to palladium has been found to give outstanding results. Alloys containing more than 20% iridium, rest palladium have surprisingly been found to be hardenable to a degree that they render spinning nozzles of a degree of hardness not known before in spinning nozzles made of alloys of precious metals.

The alloys of the above composition render spinning nozzles which warrant uniform spinning products even after being in operation for a very long time. Alloys of the instant invention combine to an especially high degree of mechanical and chemical resistance. They possess great hardness and toughness; they resist the attack of chemicals applied in the viscose process, the alkaline viscose and the acid spinning bath and the chrome sulphuric acid used for cleaning the spinning nozzles.

The qualities warrant a considerable technical progress when the alloys are applied in spinning nozzles for various processes. It could not be foretold that those outstanding qualities could be achieved by the combina tion of palladium with iridium within the indicated limits. As iridium has a higher specific weight than palladium, the iridium percentage, reckoned in volume, is even lower and yet gives a surprising effect.

The valuable qualities of the specified palladium-iridium alloys for spinning nozzles can be maintained if the alloy components are within limits replaced by other metals. Precious metal or metals, other metals of the platinum group as, e.g. rhodium and/0r ruthenium as Well as gold may replace the components up to 15%, preferably not above 10%, most preferably only up to 5%, but always the iridium content should be at least 2,938,788 Patented May 31, 1960 10%. The same limits are valid for the addition of rhenium. Copper, indium, nickel and other base metals such as iron, cobalt andmangauese may also be additioned, but only up to 3% of the palladium, preferably 1 or 2%. The above named additions may also be combined. The total amount shall not exceed 15% of the palladium and not be greater than the contents of iridium. Preferably the amount of the addition to the main constituents palladium and iridium shall be below 5% of the total alloy.

The especially high hardening efiect which can be achieved in alloys according to the invention is shown in the following table. The soft annealing is done at 1000 1200" C., following age-hardening at temperatures of between 700 and 900 C.

Vlekers Hardness After- Alloy Soft Hardening annealing It has been found that some of the alloys are satisfactorily age-hardened at temperatures of between 600 C.-700 C. The age-hardening at temperatures of between 600 and 900 C. is done for between 15 and 60 minutes.

Spinning nozzles made of the alloys according to the invention may be incorporated into a spinnerette in accordance with any of several structural arrangements. For example, the spinnerette may include a flat bottom plate into which the individual spinning nozzles are inserted. Alternatively, the spinning orifices may be bored directly in the bottom plate without using insertions. In the case of the inserted nozzles, only the inserts are of the alloy according to the invention; while in the case where the holes are bored directly in the bottom plate,

the whole bottom plate is made of the alloy. If desired,

the whole spinning pot or spinnerette may consist of the same material.

According to the invention, a spinnerette insert blank or plate blank is formed of an alloy as above described and the holes are formed therein, e.g. by drilling, when the blanks are in their comparatively softer state by first gradually soft annealing in a furnace to a temperature of between 1000 C. and 1200 C. Thereafter the spinnerette is age-hardened for between 15 and 60 minutes at temperatures of between 600 C. and 900 C.

What is claimed is:

1. A spinnerette comprising an age-hardened metal element having at least one spinning orifice, said element being made of an alloy containing 70 to 80 percent palladiurn and 20 to 30 percent iridium.

2. A spinnerette as defined in claim 1 wherein up to 10 percent of the alloy components are replaced by at least one other precious metal, such that the iridium content of the alloy is at least 20 percent.

3. A spinnerette as defined in claim 1 wherein up to 10 percent of the alloy components are replaced by at least one other metal selected from the class consisting of precious metals, rhenium, copper, indium, nickel, iron, cobalt and manganese, such that the iridium content of theralloy is at least 20 percent. a a 2,048,647 4. A s'pinnerette'as defined in claim 1 wherein .up' to 6 2,071,216

10 percent 'of the alloy components are replaced by rhenium, such'that the iridiumcontent of the. alloy is at least '20 percent. V p i 5. A spinnerette as defined in claim 1 wherein up' to References Cited in the file of this patent UNITED STATES PATENTS Feussner et al'. July 21, 1936 Powell et all. Feb. 16, 1937 Dowson Aug. 28, 1951 7 OTHERREFERENCES Proceedings of the Institute of Metals Division 1928,

10 percent of the alloy components are replaced by 10 A.I.M.E. (Carter), pages- 759-785 (New York) (pages ruthenium such thatthe iridium content of the alloy is at least 20 percent. j 1

776 and 781 relied on). 

1. A SPINNERETTE COMPRISING AN AGE-HARDENED METAL ELEMENT HAVING AT LEAST ONE SPINNING ORIFICE, SAID ELEMENT BEING MADE OF AN ALLOY CONTAINING 70 TO 80 PERCENT PALLADIUM AND 20 TO 30 PERCENT IRIDIUM. 